highendmighty:Is there an illustrated explanation about the noises old Apple II drives made when booting?

AH-OOOOOO-Gah - Chnk Chnk Chnk.

I don't know of an illustration, but I can walk you through it at a very abstract level:

1. what you call "AH-OOO-Gah" is the stepper motor for the disk read head banging against the stop. Back then, disk drives didn't have a "park" position for the read head to go to upon shutdown, nor any way of keeping track of where the head was when the drive last lost power. So, to make sure that the drive logic knew where the head was, it would instruct the head motor to step down about 30 positions. Since there were only 29 tracks on a disk, that ensured that the head would finish at track 0, and the drive logic could then move it around knowing its starting point. But if the drive had been on, say, track 6 when it powered down, it would step from track 6 to track 0, and then bang against the stop 24 more times (since it can't go past 0). (Imagine that you want to make sure your car is all the way into the garage when you pull in, but you don't know how far you should pull in, so you slam on the accelerator for 10 full seconds and squash the car against the front wall of the garage for a while, just to be sure the back end gets in.)

2. Then there were a couple of swishes, followed by a quick "swish-swish" sound. Those were the sound of the read head locating and reading in the operating system on the disk. Back then, computers didn't have a place to store operating system instructions when the power was off. Instead, the operating system would be written onto a couple of tracks on the disk and would be read into memory each time the computer powered on. (That's why you had "boot disks" and "data disks." The former had the operating system included, so you could boot from them. The latter didn't. God help you if your only boot disk got erased...) If the disk in the drive didn't have the operating system on it, the drive would just spin forever, unable to do anything else. The OS wasn't very large, so most commercial programs would include it on their disk, so you could just stick in the disk and power on (rather than locating your own boot disk, booting up, swapping out your boot disk for the commercial program, and manually loading that.)

3. The "swish-swish" sound was the end of the operating system being read in. Many commercial games and programs included, at the end of the operating system, instructions to load and run certain programs, so the computer would boot and then run the program automatically. So anything after the "swish-swish" sound was the read head going to find the first file it was directed to load and run.

When I was a kid, we went on a tour of the Sheriff's station, and they took us in a room and showed us their new computer, all punchcard activated and huge... The guy loaded in a punchcard, and the printer went to town, eventually printing up what was probably a 20x30 picture of the Mona Lisa, Not quite ASCII art, but that's the closest I can come to something I've seen since, it printed regular characters, anything on the keyboard, and overstriking to create shade and texture. Crude by today's standards, but absofarkinglutely amazing in 1980-ish.

When the pic was done, the guy doing the tour took it off the printer and asked who wanted it. Crickets commenced to fiddling... I was in shock, I held up my hand and went home with this absolutely cool piece of art. It was the coolest part of the tour, the only other things I remember is the lockers where they have to put their guns before walking into any area with prisoners(Something I call BS on to this day in the movies), and their story of how they had to change their lock system because some guy jammed the place where the striker for the lock is supposed to sit full of gum wrappers, and since it was spring-loaded, the door never latched. Guy walked out the door, easy-peasy, I guess.

The picture may exist, but sadly I am dependent on my aunt and uncle who used to be my adop ...

Heh, what a coincidence. I actually have a big "Mona By The Numbers" hanging on the wall 10 feet away. It's dated October 24, 1965 by "H.P. Peterson" It was my late father's and I'm afraid I don't know its story, but he kept it hanging for over forty years!

Not to be pedantic, well OK some will think this is nit-picking. BAUD and bps are not interchangeable. No one had a 9600 or 14400 BAUD modem, they were 9600 and 14400 bps (not Bps). BAUD is the signal rate - which Bell Labs stated was limited to 2400 BAUD using Ma Bell switching systems. After 2400 bps was reached, the signal had to be modulated to carry more than one bit per signal.

Marcus Aurelius:xenomorpheus: very nice graphic, I need to see about making one of these for my company's dial-up network service and our bearer services. I think my 286 was the first computer I had that I added a modem to so I could scour BBS systems

for you kids out there, BBS was , aw hell go wiki it already

Positive luxury. I had to solder a pair of Motorola serial I/O chips onto the motherboard of a Commodore 8032 and write my own comm routines in 8 bit assembler to get onto the local BBS.

And we were glad.

I can't remember who said it but I always liked the quote (paraphrased here): "the problem with modern programmers isn't that they can't stuff a device driver into a spare 24 bytes they found in unused scratch memory, but that they won't even try."

unyon:Actually, If you're on DSL or cable, you don't use a modem. That term refers to devices that MOdulate and DEModulate tones over a PSTN.

According to Wiki:

A modem (modulator-demodulator) is a device that modulates an analog carrier signal to encode digital information, and also demodulates such a carrier signal to decode the transmitted information. The goal is to produce a signal that can be transmitted easily and decoded to reproduce the original digital data. Modems can be used over any means of transmitting analog signals, from light emitting diodes to radio. The most familiar example is a voice band modem that turns the digital data of a personal computer into modulated electrical signals in the voice frequency range of a telephone channel. These signals can be transmitted over telephone lines and demodulated by another modem at the receiver side to recover the digital data.

I don't know about you, but I see nothing about modulating only tones over PTSN as the only possible definition for a modem.

Ah, the good old days when you could put '+++ATH' in your signature and figure out who had bought the cheap modems.

Fun fact - the Hayes command set never went away, it just evolved into GSM. If your cell phone lets you talk directly to the baseband chipset (e.g. Nokia N900) you can dial a number or send a text message with AT commands.